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<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>等差数列求和</title>
	<script type="text/javascript">
	var s=0
	for(var i=1;i<=100;i++){
		s=s+i
	}
	document.write(s);
	</script>
</head>
<body>

</body>
</html>